Red Sox pitcher Justin Masterson began a rehab assignment with Triple-A Pawtucket on Sunday, giving up three runs (two earned) on two hits and three walks in 1 2/3 innings while striking out two.
Masterson was scheduled to throw three innings on Sunday but built his pitch count up to 50 pitches before he could escape the second. Working his way back from shoulder tendinitis, Masterson is 2-2 with a 6.37 ERA and 24:19 K:BB ratio in 35 1/3 innings across seven starts.